An ever increasing number of diagnostic and interventional surgical procedures are performed using catheters introduced into the body at one or a few entry sites. By limiting the number and size of incisions, patients are able to recover more quickly and with less discomfort. With the wide range of catheters at their disposal, surgeons can operate or perform diagnostics on a great number of bodily systems, including but not limited to the vascular, nervous, and reproductive systems. Following these procedures the catheters and various accessories are removed, leaving one or more puncture sites which must be closed. These sites are often difficult to suture because they are on internal tissues or organs, are located on arterial walls below the skin, or are only accessible by a catheter. The present invention relates to procedures in which physicians do not have direct access to the tissue surrounding an opening in arterial walls or other biological tissue walls using suture.
As an example of the type of puncture closing that is problematic, consider interluminal procedures performed on the vascular system, such as an angiogram or angioplasty. The skin is punctured through to the femoral artery, and an introducer sheath is placed in the puncture. For interluminal vascular procedures, the introducer sheath is a tube having a lumen and an outer diameter in the range of 2 mm (6 F on the french catheter scale) to 15 mm (45 F) or more. Catheters are inserted through the introducer sheath and threaded towards the heart or other vascular site of interest. At the conclusion of the procedure, the catheter is removed, followed by the removal of the introducer sheath. Bleeding at the puncture site has conventionally been controlled by the use of manual compress upstream from the puncture site. Achieving homeostasis with manual compression, however, is time consuming and can result in complications. Generally, compression must be applied for one-half hour or more to achieve hemostasis. If anticoagulants are used, it may take an additional 2 to 4 hours for the effects of the anticoagulants to wear off and for compression to be effective. Direct complications from manual compression include occlusion of underlying blood vessels, which can lead to ischemia and/or thrombosis. In general, the problems and patient discomfort increase with introducer sheath size and the use of anticoagulants.
Various attempts to achieve hemostasis without the problems associated with manual compression have been made. Many of the attempts involved facilitating vessel closure using tools compatible with ancillary devices used with catheter procedures. Complicated remote controlled mechanisms for suturing are inserted through the introducer sheath following catheter removal, for example. These attempts have included the use of collagen plugs to seal the puncture, the use of complicated, remote controlled mechanisms for suturing, the application of fasteners such as hooks, clips, or staples applied from the exterior of an artery. While each of these devices can be used for closing a puncture more rapidly than manual compression, other problems can result from their use. For example, suturing devices may require many cooperating moving parts to pass the suture from one side of the artery to the other, as well as knot pushers for pushing knotted sutures or mechanisms for knot tying. Collagen plugs do not avoid all blood loss, and may increase the risk of thrombosis formation and the development of an inflammatory autoimmune reaction. Closing punctures using fasteners often involves the use of excessive force in the area surrounding their application, which can cut off or greatly reduce blood flow to the adjacent areas. This can cause ischemia and impair the healing process.
In addition many locations where closing is required are not easily visible, resulting in difficulty in placing the fastener, collagen plug, or any of the other devices described above.
Minimally invasive surgery, especially minimally invasive surgery using robotic techniques, presents further problems for known fastening techniques. In minimally invasive surgery, the surgeon has access to the body through small openings and often must work in restricted spaces or cavities. However, many known techniques are not compatible with minimally invasive techniques.
For procedures where incisions or punctures are internal to the body or percutaneous, the conventional hemostasis methods of choice are sutures and fasteners, which are usually staples. It is important that the puncture closing device work rapidly and accurately, and that it does not subject the vessels (e.g., arteries) to any undue force. The use of any of the available devices or methods can result in problems and lead to complications with the surgical procedure, which can delay patient recovery or jeopardize the patient's health. Therefore, there is a need for improved devices and methods for closing punctures or other openings in bodily tissue or organs following surgery.